Currently a number of tests exist that can diagnose patients as diabetic or pre-diabetic, including pre-diabetic conditions, such as occult pancreatic beta cell dysfunction or post-prandial hyperglycemia. Such tests include glucose, insulin, pro-insulin, c-peptide, HbA1c, fructosamine, glycation gap, 1,5-anhydroglucitol (1,5-AG), OGTT, CLIX scoring, HOMA IR scoring, and IRI scores based on combinations of AHB, L-GPC, and Oleic Acid weighted by insulin or BMI. Used alone or in combination some of these tests can detect the presence of Type 2 diabetes, pre-diabetes (metabolic syndrome) and early insulin resistance. Additionally there are tests that may detect some cases of Type 1 Diabetes (T1DM, sometimes referred to as childhood-onset or early-onset) such as anti-GAD antibody and other auto-antibodies to pancreatic islet cells, as Type 1 diabetes usually involves development of auto-antibodies.
The best current predictors of fasting normoglycemic patients who are actually at risk of developing diabetes are OGTTs and CLIX scoring of OGTTs. Both of these techniques involve testing multiple analytes at multiple time-points, requiring the patient to have a blood sample drawn at baseline (fasting), drink a beverage containing a known quantity of glucose, and subsequently contacting patient blood samples and measuring the levels of various analytes (e.g. glucose, insulin, pro-insulin, c-peptide, creatinine, etc. . . . ) at fasting baseline, and then at various time point intervals after dosing with the glucose load. Most OGTTs and CLIX scoring require a patient to remain in the doctor's office for 2 hours post dose, and most clinicians only test baseline samples and the 2 hour time point, and not the labor-intensive 3-5 additional times blood draws during the 2-hour period necessary for CLIX scoring, due to labor and cost constraints. Additionally, complicated and laborious mathematical calculations need to be performed in order to optimize detection of at-risk individuals with these techniques, and kidney function (approximated by blood creatinine levels/eGFR) needs to be accounted for, causing an additional step. In standard OGTTs, 1-hour time points are rarely obtained and tested for determination of early insulin resistance and/or beta cell dysfunction, even though it is known from the literature that impaired first-phase insulin secretion response to glucose load at the 1 hour time point is a predictor of risk of development of diabetes and resulting cardio-diabetic complications such as atherosclerosis, coronary artery disease, diabetic retinopathy, etc.
There therefore exists a need in the art for a better method for detecting the presence of likelihood of developing occult pancreatic beta cell dysfunction and post-prandial hyperglycemia.